Valve

ABSTRACT

The valve for controlling the flow of a fluid, particularly very small flows, comprising a block having at least one smooth face and at least two ducts extending through the block and terminating in the smooth face in an orifice. A slide is guided for movement substantially parallel to the smooth face and is moved, e.g. by means of a screw or pneumatically. A valve element movable with the slide is urged into sliding contact with the smooth face and a recess in the valve element is dimensioned to overlie and connect at least two of the orifices in at least one position of the slide.

United States Patent Commarmot 1 July 4, 1972 [54] VALVE 319,649 6/1885Wetherill ..251/176 [72] Inventor: Roger Commarmot, Lyon, France FOREXGNPATENTS OR APPLICATIONS 1731 Assign Rhmhulen" France 747,404 4/1956Great Britain ..137/625.25 [22] Filed: Feb. 6, 1970 PrimaryExaminer-Alan Cohan [21] Appl 9320 Attorney-Stevens, Davis, Miller &Mosher [30] Foreign Application Priority Data [57] ABSTRACT Feb. 7, 1969France ..6902908 The valve for controlling the flow of a fluid,particularly very small flows, comprising a block having at least onesmooth [52] US. Cl ..251/176, 251/278, 137/625.25 f d t least two ductsextending through the block and [51] Int Cl ..F16k3l/50 [58] Field ofSearch ..251/176, 278; l37/625.25

2,889,569 6/1959 Riester .....25l/l76X terminating in the smooth face inan orifice. A slide is guided for movement substantially parallel to thesmooth face and is moved, e.g. by means of a screw or pneumatically. Avalve element movable with the slide is urged into sliding contact withthe smooth face and a recess in the valve element is dimensioned tooverlie and connect at least two of the orifices in at least oneposition of the slide.

2 Claims, 4 Drawing Figures P'ATE'N'TEDJUL 4 m2 SHEET 10F 3 InventorROGER COMMARMOT amfwwm By M Attorneys P'A'TENTEDJUM I972 3. 674,286

sum 2 BF 3 Inventor ROGER COM MARM OT y MBM/QL; mmw

Attorneys P'A'TE'N'TEDJUL' 4 I972 3, 674 236 SHEET 3 BF 3 Inventor ROGERCOMMARMOT Y Attorneys VALVE The present invention concerns a valve forcontrolling the flow of fluids in liquid or gas form.

The very precise regulation of microflows of fluids or the strictmetering of specific quantities of fluids are extremely delicateoperations but operations which are often carried out, for example inanalytical laboratories. For this purpose, various types of valves areused, but each of them has certain disadvantages.

Regulating valves are easily obstructed by the smallest impurities, andthey do not often close in a sealing-tight manner. Furthermore, meteringvalves do not permit the precise control of small flows, and theirdesign or bulk generally make it necessary to arrange long connectingconduits which present a considerable internal volume.

According to the present invention, there is provided a valve forcontrolling the flow of a fluid comprising a block having at least onesmooth face, at least two ducts in said block, each terminating at saidsmooth face in an orifice, a slide guided for movement substantiallyparallel to said smooth face, means for effecting such movement, a valveelement movable with said slide and in sliding contact with said smoothface, spring means acting between the slide and the valve element tourge the latter against the smooth surface, and a recess in the valveelement dimensioned to overlie and connect at least two of the orificesin at least one position of the slide.

Such a valve retains substantially no solid or liquid impurities andpermits both the precise regulation of a flow or a pressure and alsooperation as a two-position valve. The valve may operate reliably, issimple to produce and maintain, and does not require either lubricationor a stuffing-box.

The invention will be better understood from the following detaileddescription, which is given merely by way of example, reference beingmade to the accompanying drawings, in which:

FIG. 1 is a sectional elevation of one embodiment of valve according tothe invention;

FIG. 2 is a section on the line A-A of FIG. 1;

FIG. 3 is a view similar to FIG. 1, of a second embodiment of theinvention; and

FIG. 4 is a similar view of a third embodiment.

The valve illustrated in FIGS. 1 and 2 is composed of a block 1 made,for example, of stainless steel, which has a smooth, plane face 2.Formed in the block are ducts 3 and 4 which terminate in orifices at theface 2. These ducts open at the other end on the lateral faces of theblock in appropriate pipe connections 5 and 6.

A valve element 7 made, for example, of polytetrafluorethylene, can bemoved in sliding contact across the face 2 of the block, the face of thevalve element in contact with the block being provided with a recess 8,which can be moved to overlie and provide communication between theorifices at the end of the ducts 3 and 4.

The valve element 7 is fixed in a stainless steel support 9 havingrounded side walls and a recess 10 in the rear. This support is an easysliding fit in a cylindrical cavity 11 in the slide 12, and a spring 13accommodated within the cavity 11 urges the valve element against thesmooth face 2 of the block.

The slide 12 is guided for movement parallel to the face 2 of the block1 and at a substantially constant distance therefrom, whatever thecompression of the spring 13 and whatever the position of the recess 8of the valve element relatively to the orifices of the ducts 3 and 4, bytwo flexible and non-extensible blades 14 and 15. These blades arearranged on either side of the two limits of movement of the valveelement and on either side of the slide in planes substantiallyperpendicular to the axis of displacement of the valve element. Theseblades are secured at their ends on the one hand to the block 1 againstwhich they are, for example, gripped by parts 16 and 17 by means of thescrew 18, and on the other hand to the slide 12 on which they arewelded. The cross-section of these blades is calculated so as to ensurethe guiding of the crossmember with a very small effort, the parts 1, 16and 17 being suitably notched to give the flexible blades the necessaryfreedom of movement. The blades 14 and 15 thus form with the parts 1 and12 substantially a parallelogram linkage.

Displacement of the valve element 7 relatively to the block 1 iseffected by a screwthreaded rod 19 which can be turned by a control knob20, and rotate within a tapped hole 21 in the part 16. Interposedbetween the rod 19 and the slide 12 is a ball 22, and spring 23,accommodated in a recess of the part 17, holds the slide 12 against theball 22 at all times. In operation, when the spring 23 is relaxed, therecess 8 of the valve element is situated opposite the duct 3 and theducts 3 and 4 are isolated from one another by the valve element 7 heldby the spring 13 against the orifice of the duct 4. When the knob 20 isturned in the sense to open the valve, the rod 19 is screwed into thehole 21, and the slide, retained and guided by the flexible blades 14and 15, is displaced parallel to the surface 2, progressivelycompressing the spring 23. This dis placement, by means of the flexibleblades 14 and 15, is carried out with minimum friction, i.e. only thefriction of the valve element 7 on the block 1. The displacement of thevalve element 7 is thus effected regularly without any shocks along thedistance detemiined in accordance with the angle through which the knob20 has been rotated. The recess 8 unmasks very gradually the orifice ofthe duct 4 until the ducts 3 and 4 are brought into communicationwithout the least narrowing of cross-section.

In FIG. 3, like parts have been given the same reference numerals as inFIGS. 1 and 2. In this embodiment the block 1 is formed with three ducts3, 4 and 24, which open on the plane, smooth face 2 at three alignedneighboring orifices, such that the recess 8 of the valve element 7 canbring the duct 24 into communication, with either duct 3 or duct 4without any narrowing of the flow passage.

The support 9 of the valve element here has no direct contact with theslide 12 but is held only by the combination of the axial conical coilspring 13 and a flexible lateral blade or leaf spring 25. The spring 13bears on the bottom of a plug 26 screwed into the cylindrical hole 11 inthe slide 12, this arrangement facilitating the assembly of the valve,and permitting regulation of the compression of the spring 13, tomaintain perfect sealing-tightness of the valve. The flexible blade 25is preferably substantially plane and parallel to the smooth face 2 ofthe block 1, its ends being secured to the support 9 and the slide 12,e.g.by spot welding.

The slide 12 is held by the two parallel leg portions 14 and 15 of aU-shaped flexible member 27, provided in its web with a suitableaperture for the plug 26. These two portions are ar ranged similarly tothe blades 14 and 15 of the valve shown in FIG. 1, and can be secured tothe slide 12 for example by spot welding. They can be directly incontact with the ball 22 and the spring 23, these being coaxial with thescrewthreaded rod 19. The displacement of the valve member 7 relativelyto the block 1 is effected in a similar manner to that described for thevalve shown in FIG. 1. If desired, the rod 19 can be externallyscrewthreaded and the part 16 internally screwthreaded withmicrometric-pitch screvvthreads to provide a regulating valve, theoperation of which is similar to that described for the valve shown inFIG. 1. However, since the flexible blade 25 ensures that the valveelement 7 is strictly integral with the slide 12, the alternatedisplacements of the valve: element 7 are effected not only without anyshock and very smoothly, but also without hysteresis.

FIG. 4 shows a valve according to the invention equipped with pneumaticcontrol and again like parts have been given like reference numerals.Certain parts have had constructional modifications made thereto. Thusthe member 7 and the support 9 together form the valve element, therecess of which is formed by a cavity 28 and two passages 29 which cancommunicate with the ducts 3 and 4. A conical cap 30 transmits thepressure of the spring 13 to the center of the support 29. Likewise, acap 31 transmits the pressure of the spring 23 axially to the blade 15and the slide 12. The blade portions 14 and 15 are united in a singleblade 27 arranged and bent around the fixed block 1.

The displacement of the valve element 7 relatively to the block 1 iscontrolled pneumatically. For this purpose, the valve is surmounted by acover 32 of pressed sheet metal welded to a plate 33, held to the block1 by means of a screw 18. The ball 22 is accommodated in an aperture inthe plate 33 along the axis of the spring 23. Within the cover 32 thereis fixed, for example by welding, a bellows 34 which is closed at itsends by an end wall 35 and by an end piece 36, the latter being formedwith a hole 37 screwthreaded to receive a hose connection (not shown).The cover 32 is provided with a side notch 38, in which is engaged theangled portion of a lever 39. The other end of this lever is appliedagainst the center of the end wall 35, and at an intermediate point itcomes into contact with the ball 22.

When the bellows is connected to a source of air under pressure and theair pressure is increased, the bellows expands, displaces the lever 39which acts on the ball 22 and moves the valve element 7,9. Displacementin the reverse sense takes place, under the action of spring 23, whenthe pressure decreases. The minimum friction and the strict guiding ofthe valve element gives this valve a remarkable sensitivity andfidelity. It may be used equally well for metering or for regulatingpurposes.

Many constructional modifications may be made to the valve according tothe invention. Thus, the valve element can be supported only by thelateral blade 25 and without the spring 13. The blades l4, l and 25 canbe replaced by any equivalent mechanical devices, such as metal rods orsheets of wires, or the blades 14 and can be articulated at their ends.The valve element may be provided with one or more recesses ofappropriate shape, for example grooves the width of which is equal tothe diameter of a duct. Thus a valve element provided with two identicalrecesses arranged side by side is suitable for a four-way valve. Theparts 1, 16 and 17 may form a single block. The valve according to theinvention may be controlled by any appropriate device, for example bymechanical devices constituted by a worm and worm wheel or a cone and aroller, or by any other device, e.g. electromagnetic, hydraulic orelectrical.

The valve according to the invention may be constructed by means of anyappropriate materials normally used, such as metals and alloys,synthetic plastic materials, graphite, ceramic materials or glass.Preferably the block 1 is metallic, for example, being made of stainlesssteel, and the face 2 is smooth and is preferably plane, ground andlapped. The valve element is preferably formed of a suitablethermoplastic material such as polytetrafluorethylene, polyethylene or apolyamide with which it is possible to incorporate fillers, such asgraphite or ground glass. The flexible blades are preferably made ofstainless steel, but may be made of any suitable metal or alloy.

The valve described is particularly suitable for regulating or meteringvery small flows with remarkable precision.

By way of example, a valve as illustrated in FIGS. 1 and 2 was made,having two ducts 3 and 4 of 0.4 mm. diameter which were spaced by 0.5mm. The valve element 7 had an external diameter of 4 mm. and athickness of 1.6 mm, and its recess 8 had a length of 1.3 mm. and awidth of 0.5 mm., its ends being rounded, and its depth being 0.5 mm.The dimensions of the other parts of the valve were in the proportionsshown in the drawings.

A three-way valve as illustrated in FIG. 3 was also constructed havingthree aligned ducts of 0.4 mm. diameter which are spaced by 0.4 mm., thevalve element 7 having a diameter of 4 mm., with a recess 8 of 1.3 mm.diameter, its depth being 0.5 mm. The dimensions of the other parts ofthe valve were in the proportions shown in the drawings.

Such valves are particularly suitable for regulating gas flows of a fewcc. per hour. With a valve element made of polytetrafluorethylene withglass filler material, they remain sealing-tight under a pressure of 5bars at a temperature of 250C. With a valve element of graphite orceramic material they can withstand even higher temperatures. Some forms0 embodiment remain perfectly sealing-tight under pressures of the orderof about a hundred bars. The valve according to the invention may beconstructed with materials which have a high resistance to corrosion.

The valves described are particularly suitable for liquids and gases,more particularly moist gases or vapors, presenting a small intervalvolume to fluids and, in an installation, may be situated directly onthe various conduits.

Since the valve according to the invention does not have a stuffing-boxand does not require any lubrication, it is particu larly simple tomaintain and its operation is very reliable. Advantageously the valveelement can be arranged in its support in such a manner that it is easyto replace. The construction of the valve is simple and relativelycheap. Since the only friction is that between the valve element and thesmooth face of the block, the efiort required to displace the valveelement is very small and at the same time the regularity and precisionof this displacement avoids any jerky movements.

When liquid or gas flows through an orifice of one of the ducts which ispartly blocked by the edge of the recess of the valve element, athrottling occurs which immediately expels any solid and/or liquidparticle which might remain attached to this orifice. The orifice,therefore, remains free of any impurities, which contributes to themaintainance of perfect sealing-tightness.

The control of the displacement of the valve element is sufficientlystrict to ensure that a valve of this kind can be used equally welleither for the sealing-tight opening or closing of a circuit or for theextremely precise regulation of the flow or pressure. A valve of thiskind, therefore, can carry out almost equally well functions whichhitherto have been regarded as incompatible.

What I claim is:

1. A valve for precisely controlling the flow of a fluid, said valvecomprising, in combination;

a. a block having at least one smooth face;

b. means defining at least two ducts in said block, said ducts eachterminating at said smooth face in an orifice;

c. a slide movable with respect to said block;

d. guide means guiding said slide for movement substantially parallel tosaid smooth face;

e. control means for effecting said movement;

f. a valve element movable with said slide and in sliding contact withsaid smooth face, said valve element being located in a member providedwith rounded side walls, said member sliding in said slide without playbetween the rounded side walls and the slide, the valve elementoverlying all of the orifices in all positions of the slide;

g. spring means acting between said slide and valve element, urging saidvalve element against said smooth face; and

h. a recess in said valve element dimensioned effective to overlie andconnect at least two of said orifices in at least one position of saidslide, the flow of fluid from one orifice to another being entirely viasaid recess.

2. A valve as claimed in claim 1, wherein said guide means comprise twosubstantially parallel and non-extensible flexible blades connected tosaid block and said slide in planes substantially perpendicular to thesmooth face, the valve element being positioned in said slide at alocation between said blades.

1. A valve for precisely controlling the flow of a fluid, said valvecomprising, in combination; a. a block having at least one smooth face;b. means defining at least two ducts in said block, said ducts eachterminAting at said smooth face in an orifice; c. a slide movable withrespect to said block; d. guide means guiding said slide for movementsubstantially parallel to said smooth face; e. control means foreffecting said movement; f. a valve element movable with said slide andin sliding contact with said smooth face, said valve element beinglocated in a member provided with rounded side walls, said membersliding in said slide without play between the rounded side walls andthe slide, the valve element overlying all of the orifices in allpositions of the slide; g. spring means acting between said slide andvalve element, urging said valve element against said smooth face; andh. a recess in said valve element dimensioned effective to overlie andconnect at least two of said orifices in at least one position of saidslide, the flow of fluid from one orifice to another being entirely viasaid recess.
 2. A valve as claimed in claim 1, wherein said guide meanscomprise two substantially parallel and non-extensible flexible bladesconnected to said block and said slide in planes substantiallyperpendicular to the smooth face, the valve element being positioned insaid slide at a location between said blades.